You must look at the Wildlife and Natural Environment (Scotland) Act 2011. Section 17(a) gives Scottish Ministers the right by regulation to establish a register of persons competent to shoot deer in Scotland. Section 17(b) states that if by 1 April 2014 the right given in section 17(a) are not exercised it falls to the Scottish Natural Heritage to review the competence among people who shoot deer in Scotland and the effects on the welfare of deer. As yet there is no sign of the Scottish Ministers regulating a Register of Competence for all persons shooting deer in Scotland but for some time there has been a committee made up of various bodies who have been deliberating and reviewing levels of competence based on a voluntary approach. On a voluntary basis the level of persons shooting deer who sit DSC Lev 1 is I believe fairly good. From what I understand the outcome of the review is leaning toward DSC lev 1 being the requirement but I would suggest that a future date would have to be set giving time to achieve this level.
There is little doubt that the movement both through applying for a deer calibre rifle and through legislation is heading toward a level of competence, Bottom line is if you want to stalk get going on lev 1 & 2.